Mainland authorities have stepped up regulation of vegetable exports to Hong Kong this year, but a survey shows more than 75 per cent of Hongkongers have no confidence in the new measures.

After a series of food scares last year, the Shenzhen Entry-Exit Inspection and Quarantine Bureau last month introduced a new management system to step up regulation of vegetable exports to the city.

From April 1, the bureau has required all suppliers of vegetables to Hong Kong to be registered with its Nanshan agricultural products wholesale distribution centre.

All vegetable exports to Hong Kong are transported to the centre, where samples are tested and the exports are labelled after preliminary inspections. The trucks are also sealed to prevent contamination before they set off to Hong Kong.

But as tests may take 40 minutes to two days, some of the vegetables will be transported to Hong Kong before the results are available.

The head of the quarantine bureau's department for vegetable inspection, Chen Xiaoying, said if samples were contaminated, the centre would immediately notify suppliers and importers to recall vegetables.

Between April 1 and May 15, Mr Chen said, the centre took more than 4,200 samples and only six were found to be contaminated with excessive pesticides or heavy metals. The contaminated vegetables had been recalled, he told Hong Kong reporters on a media tour.

Meanwhile a political party's telephone survey of 869 adults found more than three-quarters had no confidence in the new measures.

But their views were not entirely the result of doubts about the mainland authorities. Almost 40 per cent said their lack of confidence was because of food smuggling, while 36.5 per cent said local inspections were not strict enough.

'The government should carry out inspections at borders and in wholesale and retailing markets more often,' said legislator Wong Yung-kan, food safety spokesman for the Democratic Alliance for the Betterment and Progress of Hong Kong, which carried out the poll between May 12 and 17.

Nearly 60 per cent of the interviewees gave a bare pass to the Hong Kong government for its efforts in ensuring food safety. More than 30 per cent said it had totally failed. And almost 70 per cent of the respondents said they had seen little improvement in food safety since the Centre for Food Safety was set up last May.

Reliant on imports

The proportion of the city's vegetables imported from the mainland: 80%